when i was born, my dad had a commodore 64. i had learned how to use it to play games and browse file directories using command prompts by the time i was two. there was only a keyboard and joystick for input, no mouse. so everything had to be done with text prompts and i memorized all the most important ones so i wouldn't need dad's help if i wanted to play impossible mission or raid on bungeling bay.
when i was three, he upgraded to a commodore 128. a year later i programmed an entire game on my own by copying the code line by line out of an issue of "gazette" magazine. it was called "pirate cove" and it generated a 4x4 grid of ocean with a randomly placed treasure island, an enemy fleet, a monster, and a friendly port. you had to find the port and purchase guns and shovels first, find the enemy pirates and defeat them with the guns you bought, then find the treasure island and dig up the gold. everything was on 5" floppy disks and i remember going through boxes and boxes of them to find the disk with the game i wanted.
my grandpa also had an amiga at this time with totally different games, so naturally i somehow knew all the commands and how to navigate that entirely different system like a pro too when i was kindergarten age. nobody was getting between me and my games of ports of call (also, why the fuck was i so into a complex cargo shipping simulator game when i was five years old? i was such a strange kid).
at six or seven we upgraded to some IBM 386 machine that used a visual DOS shell and had a mouse and hard drive - i remember installing a point-and-click sherlock holmes adventure game that took up a whopping 80 MB of drive space, which was something like 50% of the entire capacity. the thing came on ten 3" floppy disks and took about three hours to install. i spent entire days playing that and
gorillas.
when i was 10 we got an IBM computer with a pentium chip in it and windows 95 and i got lost in tie fighter, civilization, age of empires, and (once we got non-AOL dial-up) ICQ.
i still look back and i'm kind of amazed that when i was a toddler i knew how to navigate a computer like a pro, search disks, run programs, and create entire games using only DOS text commands. it's crazy how much easier computers have become to use in the last 20 years.
Those old games were pretty tiny. It worked for a very short time before the computer died. My mom got it from a father of one of her schoolkids (she's a teacher), no idea if she ever talked to him about it. 
